X-Mozilla-Status: 0001 X-Mozilla-Status2: 00000000 Delivered-To: barryleiba.mailing.lists@gmail.com Received: by 10.58.170.71 with SMTP id ak7csp41353vec; Fri, 1 Nov 2013 11:43:54 -0700 (PDT) X-Received: by 10.68.135.132 with SMTP id ps4mr4518591pbb.171.1383331433843; Fri, 01 Nov 2013 11:43:53 -0700 (PDT) Return-Path: Received: from mail.ietf.org (mail.ietf.org. [2001:1890:123a::1:1e]) by mx.google.com with ESMTP id ai2si5511840pad.117.2013.11.01.11.43.53 for ; Fri, 01 Nov 2013 11:43:53 -0700 (PDT) Received-SPF: pass (google.com: domain of abnf-discuss-bounces@ietf.org designates 2001:1890:123a::1:1e as permitted sender) client-ip=2001:1890:123a::1:1e; Authentication-Results: mx.google.com; spf=pass (google.com: domain of abnf-discuss-bounces@ietf.org designates 2001:1890:123a::1:1e as permitted sender) smtp.mail=abnf-discuss-bounces@ietf.org; dkim=pass header.i=@ietf.org Received: from ietfa.amsl.com (localhost [IPv6:::1]) by ietfa.amsl.com (Postfix) with ESMTP id D2B7411E8169; Fri, 1 Nov 2013 11:43:52 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ietf.org; s=ietf1; t=1383331432; bh=lxFBLOmbd/AjhCfAbB925bv3EpWwxFN3rnSRNHVzCuQ=; h=From:To:Date:Message-ID:References:In-Reply-To:MIME-Version:Cc: Subject:List-Id:List-Unsubscribe:List-Archive:List-Post:List-Help: List-Subscribe:Content-Type:Content-Transfer-Encoding:Sender; b=o3tq8iVx3s756b9Oswdt4A91C38+MUkwE/9zYXP/A1Q2JTL/b1Z+7gLvvVxLDct5V eeQ8hWH0GxkVKkaPTY4egnTX+ZOx3Prpp7gdfhFEJ10RETueRQna6YSDvgMVAiaNhE WVYV2zBA+PdSE18T82ylSdYqJ66El/y/Ud/+QfMY= X-Original-To: abnf-discuss@ietfa.amsl.com Delivered-To: abnf-discuss@ietfa.amsl.com Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id BE1C111E8177 for ; Fri, 1 Nov 2013 11:43:50 -0700 (PDT) X-Virus-Scanned: amavisd-new at amsl.com X-Spam-Flag: NO X-Spam-Score: -2.717 X-Spam-Level: X-Spam-Status: No, score=-2.717 tagged_above=-999 required=5 tests=[AWL=-0.118, BAYES_00=-2.599] Received: from mail.ietf.org ([12.22.58.30]) by localhost (ietfa.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 7Jo51Te-ZJ7R for ; Fri, 1 Nov 2013 11:43:46 -0700 (PDT) Received: from mout.gmx.net (mout.gmx.net [212.227.15.19]) by ietfa.amsl.com (Postfix) with ESMTP id 74F7D11E8169 for ; Fri, 1 Nov 2013 11:43:44 -0700 (PDT) Received: from netb.Speedport_W_700V ([91.35.0.177]) by mail.gmx.com (mrgmx101) with ESMTPA (Nemesis) id 0M7kwW-1VpICc2qP2-00vSJ0 for ; Fri, 01 Nov 2013 19:43:43 +0100 From: Bjoern Hoehrmann To: Martin Thomson Date: Fri, 01 Nov 2013 19:43:46 +0100 Message-ID: References: <52717320.4000704@nostrum.com> <52733E23.2050103@alvestrand.no> In-Reply-To: X-Mailer: Forte Agent 3.3/32.846 MIME-Version: 1.0 X-Provags-ID: V03:K0:bC5Pfj/PLWnMGzBa9+QZKjTRMckmSQDdbixyUvd6M+ImWQ7CoF6 C3mntyjXj19JLFKZz+v6VMq2hddZ4Yoij4NGChUsFnE6fLY645/ep0p5x7btTDaWcR4bA1g +6Rm/K85WTYGQYHAaSzRozMZ+tUbOAc+WEvd3Zj3jGaUs1Ohy1g/Sh1aqK3xarno8E6f/YF w4W3+MkVarRTt7QxKMMsg== Cc: abnf-discuss@ietf.org Subject: Re: [abnf-discuss] addIceCandidate behavior X-BeenThere: abnf-discuss@ietf.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: "General discussion about tools, activities and capabilities involving the ABNF meta-language" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Sender: abnf-discuss-bounces@ietf.org Errors-To: abnf-discuss-bounces@ietf.org * Martin Thomson wrote: >On 1 November 2013 10:39, Bjoern Hoehrmann wrote: >> * Martin Thomson wrote: >>>See: https://github.com/martinthomson/abnf2regex >> >> Does the tool support regular grammars with left- and right-recursive >> rules? > >That is where it breaks. Not all regular expression languages support >the easy solution (backreferences to named captures), and I haven't >spent the time to work out how to express left- and right- recursive >rules the non-easy way. My tools have the same problem and I was hoping for inspiration. Last few times I searched I had little luck in finding a proper description of possible conversion processes. Perhaps the problem was that I looked mainly for grammar rewriting techniques, preserving as much of the in- put grammar as possible, rather than creating an FSA from the grammar, and then turning the FSA into a regex. Hmm doing the search right now I see "The Equivalent Conversion between Regular Grammar and Finite Automata" by Jielan Zhang & Zhongsheng Qian, published this year, that looks useful (that's #11 for 'nfa from regular grammar', the first ten results do not look relevant to the query). Also http://www.cs.um.edu.mt/gordon.pace/Research/Software/Relic/Transformations= /RG/toFSA.html If anyone else has suitable pointers, I would appreciate them. -- = Bj=F6rn H=F6hrmann =B7 mailto:bjoern@hoehrmann.de =B7 http://bjoern.hoehrma= nn.de Am Badedeich 7 =B7 Telefon: +49(0)160/4415681 =B7 http://www.bjoernsworld.de 25899 Dageb=FCll =B7 PGP Pub. KeyID: 0xA4357E78 =B7 http://www.websitedev.d= e/ = _______________________________________________ abnf-discuss mailing list abnf-discuss@ietf.org https://www.ietf.org/mailman/listinfo/abnf-discuss